Camden National Corp., the $3.7 billion holding company of Camden National Bank, reported a 16 percent increase in core operating earnings in 2015 and an 8 percent increase in core diluted earnings per share compared with the previous year.

The company said Friday that its 2015 operating earnings increased to $28.8 million, and diluted earnings per share increased to $3.49.

In the fourth quarter alone, operating earnings increased 26 percent to $7.7 million compared with a year earlier, and fourth-quarter earnings per share decreased 5 percent to 78 cents. The decrease reflects the bank’s issuance of 2.7 million shares in connection with the acquisition of SBM Financial Inc., the parent of The Bank of Maine, which was completed in October. The SBM acquisition added $840.1 million in assets, $615.2 million in loans and $687 million in deposits.